As batteries become more widely used as electrical power sources in a wide range of devices, the ability to determine the condition of a battery (including charge state) is of increasing value. Such is especially the case when the batteries are to be used in mission critical applications where they cannot be readily accessed or replaced and where battery failure would incur unusually high costs. Such applications are myriad and might include remotely located sensor equipment, satellites, smart weapons, medical and communications equipment and so forth.
The most common means of determining the condition and charge state of batteries at present is to monitor its electrical potential. This method is of limited value for batteries that have flat discharge curves, because battery voltage begins to drop only near the end of the discharge cycle, and thus cannot be reliably used to determine condition or amount of energy available during the current discharge cycle.
The present invention allows accurate determination of battery charge state, as well as the overall condition, and hence the reliability, of the battery.